The Humphrey Field Analyzer (HFA) is a visual field testing tool or apparatus which may be used for measuring the visual field of a patient and is widely used in visual field testing. The HFA includes a large dome-shaped screen and a projection system, and is configured to evaluate the ability of the patient to recognize visual stimuli at a large range of relative intensities, stimuli sizes, and field angles. One of the standard HFA programs, the 24-2, has become a useful tool for diagnosis of glaucoma and determination of the disease progression rate.
However, because the HFA was developed decades ago, drawbacks exist. For example, the HFA utilizes a primitive eye tracking device which makes it difficult to pinpoint the exact location of stimulus on a retina of the patient, thereby causing registration of the stimulus to a point on the retina to be slower or inaccurate.
Since its introduction to ophthalmology, OCT has become a widely used diagnostic tool for visualizing a structure of the retina and distinguishing between different retinal layers of the retina of the patient. For example, the OCT may be used to take structural measurements of optic nerve head, retinal nerve fiber layer (RNFL), or [NFL (nerve fiber layer)+GCL (ganglion cell layer)+IPL (inner plexiform layer)] thicknesses. These structural measurements or thicknesses may be utilized for early and diagnostics of glaucoma and its progression.